It has been proposed to use programmable resistive elements in memory cells to provide non-volatile data storage. Such resistive elements are programmable to adopt one of a plurality of different resistive states. The programmed resistive state is maintained even when a supply voltage of the memory cell is disconnected, and thus data can be stored by such elements in a non-volatile fashion.
Various types of resistive elements have been proposed, some of which are capable of being programmed by the direction of a current that is passed through them. An example of such a current-programmable resistive element is an STT (spin transfer torque) element, which is based on magnetic tunnel junctions (MTJs).
Such non-volatile elements are generally associated with a minimum data retention duration during which the data stored by these elements can be reliably retrieved. While it is possible to provide non-volatile elements with relatively long data retention durations, for example of several years or more, the longer the retention duration, the more energy consuming a write operation of the elements tends to be.
There is a need in the art for a memory device providing improved energy efficiency during write operations.